Non-linear finite element code MSC. Marc was utilized to analysis the field of stress of the Al2O3 joints brazed with composite filler materials. The properties of the filler materials were defined by using the mixing...Non-linear finite element code MSC. Marc was utilized to analysis the field of stress of the Al2O3 joints brazed with composite filler materials. The properties of the filler materials were defined by using the mixing law, method of Mori-Tanaka and theory of Eshelby to ensure the accuracy and reliability of results of finite element method （FEM）. The results show stress in brazed beam is higher than that in base material. The maximal stress can be found in the interface of joint. And the experimental results show that the shear strength of joints increases from 93.75 MPa （ Al2O3p Ovol. % ） to 135.32 MPa （ Al2O3p 15vol. % ） when composition of titanium is 3wt% in the filler metal.展开更多
Microstructure and interracial reactions of Al2O3 joints brazed with Al2O3-particulate-contained composite Ag-Cu-Ti filler material were researched by scanning electron microscopy （SEM）, electron probe microscopy an...Microstructure and interracial reactions of Al2O3 joints brazed with Al2O3-particulate-contained composite Ag-Cu-Ti filler material were researched by scanning electron microscopy （SEM）, electron probe microscopy analysis （EPMA）, energy dispersive spectroscopy （EDS） and X-ray diffraction （XRD）. The interracial reaction layer thickness of joints brazed with conventional active filler metal and active composite filler materials with different volume fraction of Al2O3 particulate was also studied. The experimental results indicated although there were Al2O3 particulates added into active filler metals, the time dependence of interracial layer growth of joints brazed with active composite filler material is t^1/2 as described by Fickian law as the joints brazed with conventional active filler metal.展开更多
In order to understand the rate-controlling process for the interfacial layer growth of brazing joints brazed with active composite filler materials, the thickness of brazing joints brazed with conventional active fil...In order to understand the rate-controlling process for the interfacial layer growth of brazing joints brazed with active composite filler materials, the thickness of brazing joints brazed with conventional active filler metal and active composite filler materials with different volume fraction of AI2O3 participate was studied. The experimental results indicate although there are Al2O3 particulates added into active filler metals, the time dependence of interfacial layer growth is t2 as described by Fickian law for the joints brazed with conventional active filler metal. It also shows that the key factor affecting the interfacial layer growth is the volume fraction of alumina in the composite filler material compared with the titanium weight fraction in the filler material.展开更多
Cu-Sn-Ti brazing filler is a new type of copper-based brazing filler for brazing diamond tools currently used in industry,but it suffers from poor wear resistance,high brazing temperature and low bond strength.This pa...Cu-Sn-Ti brazing filler is a new type of copper-based brazing filler for brazing diamond tools currently used in industry,but it suffers from poor wear resistance,high brazing temperature and low bond strength.This paper provides a way to improve the strength of dia-mond-brazed joints by adding zirconium carbide and tungsten carbide reinforcing phase particles to the Cu-Sn-Ti alloy,respectively.Dia-mond particles were attached to Q460 steel using Cu-Sn-Ti composite filler with the addition of the reinforcing phase,and experimental in-struments such as scanning electron microscope,X-ray diffractometer and energy spectrometer were used to investigate the brazed joint per-formance of the composite brazing material for brazing diamond.The results show that the addition of enhanced phase particles resulted in a metallurgical reaction at the joint of the composite brazed diamond,achieving a higher strength joint with no obvious cracks at the interface,while the addition of 15 wt.%WC resulted in excellent wear resistance and the highest hardness at the joint interface.展开更多
Al2O3l2O3 joints were brazed with a new kind of filler materials, which were formed by adding AI203 particulates into Ag-Cu-Ti active filler metal. The results showed that the material parameters (the Ti content, Al2O...Al2O3l2O3 joints were brazed with a new kind of filler materials, which were formed by adding AI203 particulates into Ag-Cu-Ti active filler metal. The results showed that the material parameters (the Ti content, Al2O3 particulate volume fraction) of the composite filler materials affected the shear strength of brazed joints. When the Ti content was 2 wt pct in the filler metal, the shear strength of brazing joints decreased with the increasing the volume ratio of Al2O3 particulate. When the Ti content was 3 wt pct in the filler metal, the shear strength of joints increased from 93.75 MPa(AI203p 0 vol. pct) to 135.32 MPa(AI203p 15 vol. pct).展开更多
Brazing,an important welding and joining technology,can achieve precision joining of materials in advanced manufacturing.And the first principle calculation is a new material simulation method in high-throughput compu...Brazing,an important welding and joining technology,can achieve precision joining of materials in advanced manufacturing.And the first principle calculation is a new material simulation method in high-throughput computing.It can calculate the interfacial structure,band structure,electronic structure,and other properties between dissimilar materials,predicting various properties.It plays an important role in assisting practical research and guiding experimental designs by predicting material properties.It can largely improve the quality of welded components and joining efficiency.The relevant theoretical foundation is reviewed,including the first principle and density functional theory.Exchange-correlation functional and pseudopotential plane wave approach was also introduced.Then,the latest research progress of the first principle in brazing was also summarized.The application of first principle calculation mainly includes formation energy,adsorption energy,surface energy,adhesion work,interfacial energy,interfacial contact angle,charge density differences,density of states,and mulliken population.The energy,mechanical,and electronic properties were discussed.Finally,the limitations and shortcomings of the research in the first principle calculation of brazed interface were pointed out.Future developmental directions were presented to provide reference and theoretical basis for realizing high-throughput calculations of brazed joint interfaces.展开更多
One of the challenges for bimetal manufacturing is the joining process.Hence,transient liquid phase(TLP)bonding was performed between 304L stainless steel and Cp-Ti using an Ag-Cu interlayer with a thickness of 75μm ...One of the challenges for bimetal manufacturing is the joining process.Hence,transient liquid phase(TLP)bonding was performed between 304L stainless steel and Cp-Ti using an Ag-Cu interlayer with a thickness of 75μm for bonding time of 20,40,60,and 90 min.The bonding temperature of 860℃ was considered,which is under the β transus temperature of Cp-Ti.During TLP bonding,various intermetallic compounds(IMCs),including Ti_(5)Cr_(7)Fe_(17),(Cr,Fe)_(2)Ti,Ti(Cu,Fe),Ti_(2)(Cu,Ag),and Ti_(2)Cu from 304L toward Cp-Ti formed in the joint.Also,on the one side,with the increase in time,further diffusion of elements decreases the blocky IMCs such as Ti_(5)Cr_(7)Fe_(17),(Cr,Fe)_(2)Ti,Ti(Cu,Fe)in the 304L diffusion-affected zone(DAZ)and reaction zone,and on the other side,Ti_(2)(Cu,Ag)IMC transformed into fine morphology toward Cp-Ti DAZ.The microhardness test also demonstrated that the(Cr,Fe)_(2)Ti+Ti_(5)Cr_(7)Fe_(17) IMCs in the DAZ on the side of 304L have a hardness value of HV 564,making it the hardest phase.The maximum and minimum shear strength values are equal to 78.84 and 29.0 MPa,respectively.The cleavage pattern dominated fracture surfaces due to the formation of brittle phases in dissimilar joints.展开更多
基金The authors are grateful for Project 50075019 supported by Na-tional Natural Science Foundation of Chinafor financial support from the visiting scholar foundation of key lab.in university.
文摘Non-linear finite element code MSC. Marc was utilized to analysis the field of stress of the Al2O3 joints brazed with composite filler materials. The properties of the filler materials were defined by using the mixing law, method of Mori-Tanaka and theory of Eshelby to ensure the accuracy and reliability of results of finite element method （FEM）. The results show stress in brazed beam is higher than that in base material. The maximal stress can be found in the interface of joint. And the experimental results show that the shear strength of joints increases from 93.75 MPa （ Al2O3p Ovol. % ） to 135.32 MPa （ Al2O3p 15vol. % ） when composition of titanium is 3wt% in the filler metal.
基金the National Natural Science Foundation of China(Grant No.50075019) the Visiting Scholar Foundation of Key Lab.in University of China
文摘Microstructure and interracial reactions of Al2O3 joints brazed with Al2O3-particulate-contained composite Ag-Cu-Ti filler material were researched by scanning electron microscopy （SEM）, electron probe microscopy analysis （EPMA）, energy dispersive spectroscopy （EDS） and X-ray diffraction （XRD）. The interracial reaction layer thickness of joints brazed with conventional active filler metal and active composite filler materials with different volume fraction of Al2O3 particulate was also studied. The experimental results indicated although there were Al2O3 particulates added into active filler metals, the time dependence of interracial layer growth of joints brazed with active composite filler material is t^1/2 as described by Fickian law as the joints brazed with conventional active filler metal.
基金Project 50075019 supported by the National Natural Science Foundation of China and also for financial support from the Visiting Scholar Foundation of Key Lab in University
文摘In order to understand the rate-controlling process for the interfacial layer growth of brazing joints brazed with active composite filler materials, the thickness of brazing joints brazed with conventional active filler metal and active composite filler materials with different volume fraction of AI2O3 participate was studied. The experimental results indicate although there are Al2O3 particulates added into active filler metals, the time dependence of interfacial layer growth is t2 as described by Fickian law for the joints brazed with conventional active filler metal. It also shows that the key factor affecting the interfacial layer growth is the volume fraction of alumina in the composite filler material compared with the titanium weight fraction in the filler material.
基金supported by the Anhui provincial Natural Science Foundation(No.2008085QE231).
文摘Cu-Sn-Ti brazing filler is a new type of copper-based brazing filler for brazing diamond tools currently used in industry,but it suffers from poor wear resistance,high brazing temperature and low bond strength.This paper provides a way to improve the strength of dia-mond-brazed joints by adding zirconium carbide and tungsten carbide reinforcing phase particles to the Cu-Sn-Ti alloy,respectively.Dia-mond particles were attached to Q460 steel using Cu-Sn-Ti composite filler with the addition of the reinforcing phase,and experimental in-struments such as scanning electron microscope,X-ray diffractometer and energy spectrometer were used to investigate the brazed joint per-formance of the composite brazing material for brazing diamond.The results show that the addition of enhanced phase particles resulted in a metallurgical reaction at the joint of the composite brazed diamond,achieving a higher strength joint with no obvious cracks at the interface,while the addition of 15 wt.%WC resulted in excellent wear resistance and the highest hardness at the joint interface.
基金The authors are grateful for Project A50075019 supported by the National Natural Science Foundation of China and also for fi-nancial support from the visiting scholar foundation of key lab. in university of China.
文摘Al2O3l2O3 joints were brazed with a new kind of filler materials, which were formed by adding AI203 particulates into Ag-Cu-Ti active filler metal. The results showed that the material parameters (the Ti content, Al2O3 particulate volume fraction) of the composite filler materials affected the shear strength of brazed joints. When the Ti content was 2 wt pct in the filler metal, the shear strength of brazing joints decreased with the increasing the volume ratio of Al2O3 particulate. When the Ti content was 3 wt pct in the filler metal, the shear strength of joints increased from 93.75 MPa(AI203p 0 vol. pct) to 135.32 MPa(AI203p 15 vol. pct).
基金financially supported by National Natural Science Foundation of China(52475347,52071165)National Foreign Experts Program of Ministry of Science and Technology(G2023026003L)+2 种基金China Postdoctoral Fund(2023M740475)Henan Provincial Science and Technology Joint Fund(Industry)(225101610002)Program for Science&Technology Innovation Talents in Universities of Henan Province,China(22HASTIT026),International Science and Technology Cooperation Project of Henan Province(242102521057),China,the Program for the Top Young Talents of Henan Province,China and Frontier Exploration Project of Longmen Laboratory(LMQYTSKT016),China.
文摘Brazing,an important welding and joining technology,can achieve precision joining of materials in advanced manufacturing.And the first principle calculation is a new material simulation method in high-throughput computing.It can calculate the interfacial structure,band structure,electronic structure,and other properties between dissimilar materials,predicting various properties.It plays an important role in assisting practical research and guiding experimental designs by predicting material properties.It can largely improve the quality of welded components and joining efficiency.The relevant theoretical foundation is reviewed,including the first principle and density functional theory.Exchange-correlation functional and pseudopotential plane wave approach was also introduced.Then,the latest research progress of the first principle in brazing was also summarized.The application of first principle calculation mainly includes formation energy,adsorption energy,surface energy,adhesion work,interfacial energy,interfacial contact angle,charge density differences,density of states,and mulliken population.The energy,mechanical,and electronic properties were discussed.Finally,the limitations and shortcomings of the research in the first principle calculation of brazed interface were pointed out.Future developmental directions were presented to provide reference and theoretical basis for realizing high-throughput calculations of brazed joint interfaces.
文摘One of the challenges for bimetal manufacturing is the joining process.Hence,transient liquid phase(TLP)bonding was performed between 304L stainless steel and Cp-Ti using an Ag-Cu interlayer with a thickness of 75μm for bonding time of 20,40,60,and 90 min.The bonding temperature of 860℃ was considered,which is under the β transus temperature of Cp-Ti.During TLP bonding,various intermetallic compounds(IMCs),including Ti_(5)Cr_(7)Fe_(17),(Cr,Fe)_(2)Ti,Ti(Cu,Fe),Ti_(2)(Cu,Ag),and Ti_(2)Cu from 304L toward Cp-Ti formed in the joint.Also,on the one side,with the increase in time,further diffusion of elements decreases the blocky IMCs such as Ti_(5)Cr_(7)Fe_(17),(Cr,Fe)_(2)Ti,Ti(Cu,Fe)in the 304L diffusion-affected zone(DAZ)and reaction zone,and on the other side,Ti_(2)(Cu,Ag)IMC transformed into fine morphology toward Cp-Ti DAZ.The microhardness test also demonstrated that the(Cr,Fe)_(2)Ti+Ti_(5)Cr_(7)Fe_(17) IMCs in the DAZ on the side of 304L have a hardness value of HV 564,making it the hardest phase.The maximum and minimum shear strength values are equal to 78.84 and 29.0 MPa,respectively.The cleavage pattern dominated fracture surfaces due to the formation of brittle phases in dissimilar joints.
